Ahoy there! Quick question about I/O and an exception that's throwing me off

Hey Everyone,
In a basic programming class and its my first time doing this kind of thing. We're writing a program where users input the details of their birthdate and then the program spits it back out in a particular format. I hope this doesn't come across as trying to get my homework done for me, I'm just struggling with the class and could use some sage advice.